Celery is an asynchronous task queue allowing easy distributed job execution in Python. This talk will, after a short introduction to Celery, share what we learned when we used it as the backbone for the campaign automation module of Exponea experience cloud. Serving over a hundred millions of our client's customers across the world with incredibly diverse use cases, we have heavily used some of Celery's most obscure functionality in often unintended ways. Join us for a bumpy ride towards a stability and scalability and learn many insights useful if you ever need to run some serious asynchronous jobs yourself. Barf bags not included.